edison



May 3,1927. TA'EDISO Re.16,614-

STORAGE BATTERY Original Filed March 12, 1924 INVENTOR ATTORNEY y Reuma May s, 1'927. i

UNITED STA THOMAS .L EDISON,

1N GQBPORATED, 0F WEST ORANGE, NEW JERSEY, CORPOBATTONOF NEW JERSEY.

v STORAGE BATTERY.

DrIgInl No. L, dated February 11, 1925, Serial No. 898,633, Bled March 12, 1924. Application for reissue iled February 8,

My invention relates. to storage batteries and more particularly to storage battery cells having the same general characteristics as the cell disclosed in Patent No. 1,377,194, 4granted to me on Ma 10, 1921.l Althoughdesig'ned especially or use in connection with Edison storage battery cells wherein nickel hydroxide is opposed to finely divided electrolytically act-ive iron or oxide of iron in an alkaline solution as the elect-ro1yte,'it lis to be distinctly understood that my' inventionis not limited in its application to cells of this type.

In-,the cell disclosed. in the patent referred to, a battery Vpile of special construction is employed infthe place of the usual plate assembly in Edison storage battery cells. This battery pile lcomprises a series of ver thin conductiye contactA sheets, preferab y of nickel, separated by insulating sheets of asbestos paper, 'with thin fiat layers of nely' divided active material respectively disposed between the surfaces of each ofthe nickel sheets-and the adjacent asbestos sheets, the. whole being heldjtogether undergreat essure with the layers of active materiaP in irm, close surface contact with the repective nickel Sheets.- The .layers of active material for the negative elements, prefer'Y ably consist of electrolytically finely divided iron or oxide ofiron, preferably mixed'with a small amount of mercury, and 'the layers '1 off active material for the positive elementspreferably consist offinely divided nickel hydroxide. 'Other suitable active materials may, however, be employed 4instead of the finely divided iron and nickel hydroxide; for example, in place of finely divided iron as the active material for thenegative elements, nely divided cadmium or cobalt may be employed; and in place 'of nickel hydrox ide as the active material for the 'positive elements, an oxide of cobalt may be em" ployed. n v

In lnaking up a battery pile such as that described above, I have heretofore proceeded las follows: The asbestos insulating sheets used inthe battery pile were first coated on one side with a thin layer of finely divided iron'or oxide 4of iron, and on the Y other side with a thin layer of nickel hydroxide. These coated asbestos sheets were then-'subjected to enormous pressure so las to' compact the layers of active material and vtive electrode elements of the pile.

1928. Serial No. 85,80.

form thesam' with very smooth fiat surfaces.' The proper number of coated asbestos sheets were then superimposed with one of the thin nickel contact sheetsbetween each two adjacent asbestos sheets in such a manner that one of each two adjacent nickel sheets Was engaged on each side with a layer ofthe electrolytically active iron or oxide 0F WEST ORANGE, NEW' JERSEY, ASSIGNOR TO THOMAS A. EEISON.,

lpile and nuts threaded on said rods. These rods served as the poles of the battery. pile, for one of said rods contacted only the contact sheets of the negative electrode elements of the pile and? the other of'said rods contacted' only the contact sheets of the posi- This Was accomplished by providing the Contact sheet of each electrode element with two openings through which 'the said rods respectively extended, the opening or'one rod being. of such size that the rod fitted very f closely therein, and the opening for the other rod being .of somewhatgreater size so that the rod which extended therethrough was y spaced from the wall of such opening.

I find, however, that cells constructed as above described become unduly heated bothlon charge and discharge, that the capacity of v such cells, especially at Ahigh discharge rates, Ais considerably below that which should be obtained, and that the capacity decreases tosome extent with the length of time the cells are in use.. I believe these conditions to be correctly explained as follows: In cells so constructed the surface contact of the nickel conductive sheets and the layers of activematerial-engaging the same is so close and' said layers of lactive material are so compacted because ofthe great pressure to which said layers were subjected in forming,

the battery piles, and also because of the pressure under which the piles are maintained, that it is extremely diicult for any appreciable amount of the electrolyte to gain electrolyte in the cells.

access to the layers of active material except such portions thereof las are directly exposed to or closely adjacent the body 'of the Moreover, the internal resistance and heatingo-f such cells, both on charge and discharge, are materially increasedby osmotic action. This action takes place in the direction of the flow of currentand whenl the cells are on charge has the effect of driving the small amount of electrolyte Whichmight otherwise reach those portions of the layers of active material ofthe positive electrodeelements Which are remote from the body of the electrolyte, away from the adjacent-surface portions of the nickel contact sheets of such elements, While when the cells are discharged it has the effect of driving the electrolyte which might otherwise reach thecorresponding portions of the layers of active material of .the negative elements, away from the adjacentsurface portions of the nickel contact sheets ofthese elements. dien the electrolyte is thus driven away from the nickel contact sheets of the electrode elements, the adjacent active' material is rendered practically dry and as such material is a very poor conductor when dry, the electrical resistance thereof and the internal resistance of the cells Will thereupon be greatly increased. That the foregoing explanation is correct is substantiated, in part at least, by examinations which I have made of cells of the type described after the same have been in use, which examinations show the active material adjacent the edges of the different layersthereofto be tfully formed andthe material remote from' the edges of thev said layers to be either onlyartially formed or in such condition that 1t is clear thatsuch material was not being acted on by the electrolyte. It is therefore obvious that in such cells the circulation of the electrolyte and the access thereof to all ing the circulation of the electrolyte as to insure a constant and copious `supply of electrolyte to all portions of the active material of the electrode elements both oircharge and discharge. l have discovered that the foregolng object may be attained to a marked-degree in a cell such as described, by providing an arrangement wherein the active material between each of the conductive members or sheets and the-'adjacent insulating members or sheets is so disposed to facilitate rthe Circulation of the electrolyte through such,

active material and between said conductiye and insulating members or sheets so that the electrolyte may readily reach all portions of the active'material, and preferably j an arrangement in which the active material 'formed grooves which are properly arranged in the cell. Where circulatingpassageivaysfconsisting of grooves of this char acter are employed, such grooves are preferably formed in the active material by the use of suitablyshaped die's when subjecting the asbestos sheets coated with the active material to the heavy initial pressure, prior to assembling the battery pile..

' Other objects and features of my invention Will behereinafter more fully described and claimed. V

In order that my invention may bey more" clearly understood, attention is directed to the drawing accompanying and forming a part ofthis specification and in Which:

Figure 1 is an enlarged, fragmental sectional vieW of alstorage battery cell of the type disclosed in my Patent No. 1,377,194, referred to above, wherein the arrangement for facilitating the circulation of the electrolyte consists in the provision'of the active material With passageways in the form of grooves of the special type above referred to;

Figure 2 isv a plan view of 'one of the coated asbestos insulating sheets of the cell shown in Figure `lrprior to, the assembly Alhereof in the'battery pile; and

Eigure 3 is an enlarged sectional view 0I a number of the elements in the battery pile 'of thecell shown in Figure 1.

Referring to the drawing, reference character l represents the asbestos insulating vand separating sheets Whichare disposed be# tween the adjacent' negative and positive electrode elements of the battery pile. Prior to the assembly of the pile leach of a plurality of these asbestos sheets is coated on one side or face With Aelectrolytically active iinely divided iron 'and on the opposite side or facewith finely ,divided nickel hydroxide. Each of the coated. sheets is then subjected between a pair of d ies toa pressure of several thousand pounds per square inch.

flVlien the arrangement for facilitating the circulation of the electrolyte comprises passageways in the active material in the form of grooves such as shown in the construction illustrated, the faces of these dies are preferably provided With'similar series of ribs or ridges, and in using the dies the same les are arranged with the corresponding ribs or ridges thereof in alignment so that in sub- `jecting the coated sheet to pressure therebetween, as described, substantially the entire surface portions of the'4v active 'material on both sides of the sheet will have iinpressed orformed therein similarseries of closely spaced grooves 30 of shallow depth with the .corresponding grooves in the active material on opposite sides of said sheet in alignment. The grooves of each series. are preferably parallel and preferably extend in the direction of. the narrow dimension of the coated sheet,'where the latter is rectangular in shape, as shown in Figure 2. If desired, however, additional grooves extend.- .ing lengthwise of the coated sheet and intersecting the grooves sho'wn, may be p and, especially where the coated s eets differ in shape from v'those-shown, other arrangements such as passageways orgrooves of various other shapes, sizes and disposi'- tion may be used. A plurality of coated asbestos sheets after being subjected 'to the pressure and grooved as described, 'together with a plurality of thin contact sheets, preferably formed of nickel, are then assembled into a battery pile'A, with the corresponding grooves 30 in the various layers of 'active material in alignment. The batter pile A comprises -a'plurality of superpo and alternately arranged negative and positive electrode elements, each of the negative elements consisting of a thin contactvsheet orv foil 4, preferably of nickel, and two layers 5` of electrolytically active finely divided iron respectively disposed on opposite sides of the sheet or foil 4; and each 'of the positive elements consisting of athin contact sheet or foil 6, similar to the sheets or foils 4 of the negative elements, and two't-hin layers 7 of finely" divided nickel hydroxide being, of course,

respectively disposed on opposite sides. of the sheet orfoil 6 and in contact therewith. The insulating sheets of asbestos paper Aare respectively disposed between the negative and positive elements, each coated on one side with a layer 5 of nelydivided iron which is in contact with the adjacent thin nickel sheet. or foil 4, and on its other side with a layer v7 of nickel hydroxide which is in contact Awith the adjacent nickel sheet or 'foil 6. Strongheavy nickel-plated' pressure plates are respectively disposed at the .opposite ends ofthe superposed negative and positive elements; only one of these pla-tes, indicated by reference character 9, being shown. ,The contaet sheet or teil4 of each ofthe outermost negative elements is not in contact at its outer surface with a layer of finely di` vided iron but is merely separated and insulated from the adjacent pressure plate by an uncoated insulating sheet 10. Reference Vcharzwtei 11 represents oneof the two rods poles of these sheets against the Wall of thev opening provided therefor in-'each of the contact sheets 4 of the negative' electrode elements, but the opening 12 provided Ain each of the vcontact sheets 6 of the positive electrode elements for said pole 11 is of such size that the pole Will be'spaced from the wall of this opening as clearly shown in Figure 1. The asbestos sheets land 10 and tlie layers of active ma-A terial 5 and 7 arealso provided with openings ,13 and 14 through which the poles extend and which are ofsuch size that the will not contact the Walls of these 6 for the positive pole, not shown, will, of course, be of such size that the positive pple Vwill closely engage the Iwalls of these openings, while the openings in the Contact sheets 4 of the negative electrode elements provided `for the reception of the positive pole will be of suoli size that'said pole Will not engage the walls thereof. Each of the rods or poles is insulated from each of the pressure plates at the end of the battery pile by'a hard rubber bushing 15 and a hard rubber .Washer 16. y

In the particular cell shown. and described, the grooves r30 in the faces of the layers of active material which are adjacent the contact sheets .4 and 6 constitute passageways extendingthrough the battery pile and located between spaced surface s ections of active material having close, intilfor the electrolyte to work its way through the active material for any great distance. Therefore in the operation of the cell,A there will be a suiicientl free and rapid circulation' of the electro yte to ensure a 'constant and copious supply thereof to all portions of the active material. Accordingly substantially all of ,the active material will be fully formed'soon'after the cell is put into operation, and thereafter practicallyall of such material i'vill'beactive Moreover because of the. improved circulation of the electrolyte, the deleterious effects of osmotic action are lar ely obviated and the'heat generated'in the attery pile isdissipated more rapidly and effectively. In a battery cell embodying the present invention, the in-' ternal resistance is reduced, the capacity, especially at high discharge rat'es is greater, 'and the cell is generally more eflicient in operation. l

It is to be understood that my invention is ,li ily circulate through the battery y* not limited to the construction shown and specifically described herein, vbut that such construction is merely illustrative of the manner in which the active material may be disposed or arranged to facilitate the circusuch conductive member thereby providing passageways to facilitate .the circulation of the electrolyte through the active material, substantially as described.

2. In a storage battery cell, a conductive memberan insulating member and active material held under pressure between said members, said active materialhaving means whereby Ithe .surface Contact thereof with the conductive member is interrupted for facilitating the circulation of electrolyte through the lactive material, substantiallyn j j spaced shallow grooves to facilitate the ciras described.

In a: storage battery-cell, a conductive sheet, an insulating sheet and active material held under pressure between said sheets, said active material having spaced surface sections in close, intimate contact with said conductive sheet the spaces between said surface sections facilitating r'the circulation of electrolyte tlirou'glithe active material, substantially as described.

Il. In a storage battery cell, a conductive member, an insulating member and active material between said members, said active material being provided with spaced surface sections engaging saidconductive member and with passageways intermediate said surface sections for facilitating the circulation ofelectrolyte through the active material, and means securing said members together whereby the active material is maintained under pressure with the said 'spacedsurface sections thereof in close, intimate contact 'with said eoiidiuitive member, substantially as described.

5. In a storage battery cell, .a pile comprising a plurality of alternately disposed positive and negative elements and insulating members lrespectively disposed between the adjacent elements, said elements each comprising a conductive. sheet and active material respectively disposed adjacent the opposite surfaces ofsaid sheet, the aetive material adjacent eachsurface of said sheet having spaced surface sections in close,

intimate contact with such surface and with passageways intermediate the said surface sections and extending through the pile adjacent such sheet for facilitating the circu'- lation of electrolyte through the active material, substantially as described. A

6. In a'storage battery cell, a plurality of alternately .disposed positive and negative elements, and insulating sheets respect-ivel disposed between the adjacent elements, eac ofy said elements comprising a conductive sheet vand active material having spaced surface sections engaging said sheet and passageways intermediate said surface Sections for facilitating the circulation of electrolyte through the active material, the corresponding passageways in the active material of all said elements being in alignment, substantially as described.

7. In a storage battery cell, a conductive member, an insulating member and a layer `of active material between said members, the surface of said layer vadjacent the con- -ductive member being grooved to facilitate the circulation of electrolyte through such layer, substantially-as described.

8. In a storage battery cell, a.' conductive member, an insulating member and a layer of active material between said members, the surf'ace of said layer adjacent the conductive member being provided with a series of culation of electrolyte through Such layer, substantially as described. f

9. In a storage battery cell, a. conductive member, an insulating member and a layer of active material between said members, the A surface of said layer adjacent the conductive member being grooved to facilitate the circulation of electrolyte through suchlayer, and means for securing said members together whereby the active material is maintained under pressure firmly .in engagement with'- said conductive member, substantially as described.

l0. In a storage battery cell, a conductive member, an insulating member and a layer of active material between said members,'the surface of said layer adjacent the conductive member being provided with a series of spaced grooves to facilitate the circulation of electrolyte through such layer, and means securing said members together whereby the portions of the active material between the grooves in said layer are maintained undei pressure firmly in engagement, with said conductive member, substantially as described.

yll. In a storage battery cell, a plurality of alternately disposed positive.and negative elements, each of said elements comprising a conductive sheet and a layer of finely divided activevmaterial engaging said sheet,

the surfaces of the layers of active material adjacent the conductive sheets being provided with similar series of grooves to facili- 10 l faces of said la ers of active adia- .4

. [cent said sheet A series of rooves to 'facilitate the circulation. of electro yte throu h such layers, the corre' spondin grooves o the two layers of active materia engagin 12. In a storage of alternately disposed positive and negatlve elements, each of said elenprents comprising a conductive sheet aid layers of finely xii-.- '-vided` active material respectively eging conductive member being vseries of spaced parallel grooves to facilitate v Y tate thebcrciilation of-electrol 'through lsuch layers, and the c'or1-1 a spo`n grooves in'psaid la ers being in alignment, substantially as escribed.

battery cell, 'a plurality the opposite surfaces of said sheet, suring provided with similar said sheet being in aligny as described.

ment, substantial 13. In a storage battery cell, a nat eondue# Y tive member, an insulating member and a 2o layer of active material between said members, `the surface4 of said layer adjacent-the provided with a the circulation of electrolyte tlirou h such layer, and means said mein rs to gether whereby the portions of the active material between the grooves therein are maintained under-pressure firmly in engage-l ment with saidconductive member,- substantially as'des'cribed.

14. In astorage battery cell a plurality of alternately disposed positive and negative elements, each of'said elements comprisi a conductive sheet and layers o f finely divi edl active :material maintained under pressure Afirmly in contact with the opposite surfaces fof said sheet respectively; the surface of each of said' .layers o f active material adjacent,4 t

said providedwith a series of spaced grooves to. facilitate the circulation of electrolyte hrougli' layer, substans 1e; ay; of

la EDISON. 

